Field of the Invention
The present invention relates to an air admittance valve preventing mephitis (noxious gas) overflow, and particularly relates to the field of using an air intake apparatus.
Description of Related Art
According to the prior art air intake pipe structure shown in FIG. 5, which is formed of a pipe body 50, air intake channeling functions are performed for all kinds of apparatuses via connection of apparatuses with the pipe body 50. Also in FIG. 6, a structure formed of a pipe body 50 and a pipe cover body 60 is shown, wherein a net surface 61 is located on top of said pipe cover body 60. The pipe cover body 60 covers the top of the pipe body 50, so that air is introduced into the pipe body 50 through the net surface 61 of the pipe cover body 60. Moreover, although the apparatus coupled through the pipe body 50 performs air intake channeling functions for all kinds of apparatuses.